论文标题
通过广义的luneburg镜头聚焦的超级波
Ultralong Wave Focusing via Generalized Luneburg Lens
论文作者
论文摘要
在本文中，提出了一种基于广义Luneburg镜头（GLL）概念的新型梯度指数（Grin）结构镜头。该镜头允许实现双重焦点并在两个焦点之间的能量流进行定位，从而实现了超大的聚焦。双线笑镜由两个同心圆形区域组成，其厚度在薄板结构中定义不同。两个同心圆形区域设计为实现具有不同曲线的折射率的连续更改。进行数值模拟和实验研究，以获得最大位移幅度，最大最大（FLHM）的全长以及晶状体区域焦点区域的一半最大（FWHM）的全宽度。结果表明，在宽带频率范围内可以实现超大的亚波长焦点。此外，我们的结果表明，FLHM和FWHM可以通过GLL的焦距设计来定制。这提供了一种简单而灵活的方法，可以为许多应用程序设计GLL聚焦特性和能量分布。
In this paper, a novel gradient index (GRIN) structural lens based on the concept of generalized Luneburg lens (GLL) is proposed. This lens allows for the realization of double foci and localization of energy flow between the two focal spots, thereby achieving ultralong focusing. The double-foci GRIN lens consists of two concentric circular regions with varying thickness defined in a thin plate structure. The two concentric circular regions are designed to realize continuous change of refractive indices with different profiles. Numerical simulations and experimental studies are performed to obtain the maximum displacement amplitude, full length at half maximum (FLHM), and full width at half maximum (FWHM) of the focal region of the lens. The results demonstrate that ultralong subwavelength focusing can be achieved for a broadband frequency range. In addition, our results show that the FLHM and FWHM can be tailored through the design of the focal length of the GLL. This offers a simple and flexible approach of engineering the GLL focusing characteristics and energy distributions for many applications.
